1. Field of the Invention
The present invention is directed to dispensing cabinets and, more particularly, to dispensing cabinets having drawers of the type which are opened and closed under the control of a computer to control access to the contents of the drawer.
2. Description of the Background
In large medical facilities, inventories of medical supplies are normally held in centralized storage locations or pharmacies which are often far removed from decentralized storage locations. It is at the decentralized storage locations, e.g. a nurses station, that dispenses for patients are typically performed. To facilitate dispensing of medications and supplies for patients, a variety of dispensing systems have been proposed. For example, several dispensing systems have been proposed which employ a cart or cabinet which is located at the decentralized location.
Of particular interest to the present invention are dispensing systems which dispense pharmaceuticals and other items which require close monitoring and control. A variety of schemes have been proposed for providing secured access to pharmaceuticals that are held within such dispensing systems, including locking the pharmaceuticals within the carts or by allowing access to only one item at a time, commonly referred to as xe2x80x9csingle dosexe2x80x9d or xe2x80x9cunit dosexe2x80x9d dispensing.
One such system is described in U.S. Pat. No. 5,014,875 titled xe2x80x9cMedication Dispenser Station.xe2x80x9d That system comprises a multiple-drawer cabinet for holding pharmaceuticals, with each drawer containing a covered, multiple-compartment carousel. Access to each drawer and each carousel compartment is controlled to allow access to the contents after a predetermined code or other information has been entered into a controller.
Another system is described in U.S. Pat. No. 4,847,764 titled xe2x80x9cSystem for Dispensing Drugs in Health Care Institutions.xe2x80x9d That dispensing system involves a computer system connected to a number of remote medication dispensers. The computer system includes software for, among other things, controlling access to the medications, identifying potentially dangerous drug interactions, and assisting with inventory control. The remote medication dispensers comprise a number of cabinets, with each cabinet holding a number of unit dose medication packages.
U.S. Pat. No. 5,927,540 titled xe2x80x9cControlled Dispensing System and Methodxe2x80x9d discloses apparatus and methods for dispensing articles in a controlled manner. In one embodiment, the invention provides an apparatus comprising a cabinet defining an enclosure. At least one drawer is attached to the cabinet and is configured to slide in and out of the cabinet. The drawer contains an array of compartments. At least one lid is attached to the drawer and is configured to slide forward and backward with respect to the drawer. Each drawer further includes a locking mechanism which may engage the lid at selective locations along the lid. With this arrangement, the locking mechanism may engage the lid to prevent movement of the lid relative to the drawer after a certain compartment has been exposed. Each drawer further includes a distance sensor for detecting the distance traveled by the lid relative to the drawer. A controller is placed in communication with both the locking mechanism and the distance sensor. The controller sends a signal to actuate the locking mechanism after the lid has been moved to expose a desired compartment. In that manner, the lid may be moved to allow access to a compartment containing a desired article or medical supply. The locking mechanism then engages the lid to prevent further movement of the lid, thereby preventing access to additional compartments.
U.S. Pat. No. 6,109,774 titled xe2x80x9cDrawer Operating Systemxe2x80x9d discloses a drawer operating system for allowing graduated access to consecutively spaced bins, partitioned in a drawer, so that access to the bins is controlled. The invention is housed in the rear of each drawer. It tracks the previous activity of the drawer and, when later accessed, allows the drawer to be pulled open to a length that will expose the contents of a bin either not emptied in previous openings or not uncovered in previous openings, retaining the other item-filled bins inside the cabinet and secure from access. In the preferred embodiment, the drawer is driven from its fully-closed position to a slightly-opened position of one inch or so to indicate to the user that this particular drawer may be opened further by merely pulling it outward. When the drawer is later pushed toward its closed position, it is stopped short of full closure and subsequently slowly driven closed into a locked position in the cabinet. This latter feature prevents xe2x80x9cslammingxe2x80x9d of the drawers into the cabinet and reduces the potential for damage to the contents therein.
While such systems provide for unit dose dispensing, the need exists for a unit dose dispensing cabinet that provides a means of accessing the medications in the event of a power failure or the need arises to override the computer controlling the cabinet. Additionally, it is desirable for the dispensing cabinet to be refilled or restocked in a convenient manner that reduces the likelihood that a restocking error will occur.
One aspect of the present invention is a drawer for use in a dispensing cabinet. The drawer is comprised of a tray movable between an open position and a closed position. An insert, approximately the length of the tray, is carried by the tray and defines the volume of the drawer. A lockable lid, i.e., mechanically lockable or sealable with an adhesive seal, is carried by the insert. A release mechanism is provided to connect the insert to the tray in a manner that allows the insert to be easily disconnected from the tray. Removal of the insert enables inserts to be swapped so that inserts from which inventory has been depleted can be replaced with stocked inserts. Eliminating the need to transfer inventory from a restocking package to the insert eliminates the possibility of errors occurring from such a transfer.
Another aspect of the present invention is a dispensing cabinet having unit dose drawers of the type previously described. The dispensing cabinet comprises an input device, an output device and a computer connected to the input and output devices. A cabinet has a plurality of drawers, at least one of the drawers being a unit-dose dispensing drawer capable of dispensing a unit-dose. Each unit-dose dispensing drawer is comprised of a plurality of individual drawers, each individual drawer comprising a tray drivable between an open position and a closed position. An insert is carried by the tray. The insert defines one or more individual compartments each having a lockable lid. The insert is approximately the length of the tray and defines the volume of the drawer. A release mechanism is provided for connecting the insert to the tray. A self locking worm gear driven by a motor is connected to the tray through a clutch to provide a mechanism for driving the tray. During normal operation, the friction provided by the worm gear renders the drawers unmovable unless they are driven by the motor. In the event of a power failure or other problem, the clutch can be used to disengage the tray from the worm gear so that the drawers can be opened and closed.
Another aspect of the present invention is a method of restocking a unit dose drawer of a dispensing cabinet. The method is comprised of the steps of releasing a first insert that defines the volume of an individual drawer from a tray, connecting a filled insert to the tray from which the first insert has been removed, and unlocking or unsealing the lid of the filled insert. The first insert may then be delivered to a storage location for filling. After filling, the lid is locked and the filled first insert is delivered to a dispensing cabinet.
The present invention provides a convenient apparatus and method of refilling or restocking a dispensing cabinet in a manner that reduces the possibility of errors. The cabinet can be operated in such a manner that the drawers of the dispensing cabinet may be manually operated in the event of a power failure or problem with the cabinet. Those, and other advantages and benefits, will be apparent from the Description of the Preferred Embodiments herein below.